Guess Who I Saw Today

(1) Look for the source of the Nightstalker stealth mutation. (2) (Optional) Ask Lily to help you investigate the Nightstalker mutations. (3) Tell Doctor Henry you've discovered a potential cause for the Nightstalker mutations. (4) Talk to Lily about participating in Doctor Henry's experiment. (5) Tell Doctor Henry to proceed with the experiment once Lily is present. (6) Wait for Doctor Henry to complete the experiment. (7) Speak with Keene and try to defuse the situation. (8) Speak with Doctor Henry. (9) Decide whether or not Lily should continue to wear the Mark II prototype and inform Doctor Henry.

At the far western reaches of the map, there's a settlement called Jacobstown. Jacobstown is a bit of an anomaly in the Mojave Wasteland, since it's a town run and occupied almost entirely by Super Mutants and Nightkin. Getting to Jacobstown is actually fairly annoying, since you'll have to follow a wandering road through the mountains in order to reach it. But once you do, head forward through the settlement towards the gigantic building towards the back. Within, head right on the first floor to find the town's only non-Super Mutant/Nightkin residents, a human named Dr. Henry and his lab assistant, a Ghoul named Calamity. You can speak to Dr. Henry about all sorts of issues, but ultimately, you'll find out that he's here working on the solution to a problem that's been plaguing the residents of Jacobstown, and indeed Super Mutants and (especially) Nightkin around the Wasteland.

The chronic use of Stealth Boys by the Nightkin community has created a sort of sickness that's endemic with most of their kind. Dr. Henry wants to get to the bottom of what's going on with the Nightkin, and he suspects that the source of the sickness -- and more importantly, the solution therein -- rests with the Nightstalker population that inhabits a cave to the north of town. Dr. Henry requests that you go to the cave to investigate things there, and you should oblige. Be sure to take him up on his optional request, too, to bring the Nightkin named Lily there with you. You'll need to clear space for her in your group of followers (if you have two with you, that is). You can find her outside; just follow your compass instructions. A good combination of followers to bring with you for the duration of this side quest is Lily and Rex, since they both specialize in melee, close-quarters combat.

Once you've acquired Lily, it's time to find an entrance to the cave in question. The cave, named Charleston Cave, is clearly marked on your map, but you can't take a straight northerly route there. Instead, you'll need to leave the confines of Jacobstown. Once you're on the outside of the wooden stakes surrounding the town (as a sort of makeshift fence), simply meander your way northward towards the mountains. You'll run into the non-descript cave entrance before long (there should be a random heart painted on a rock in front of the entrance). Once you're there, there's nothing left to do but to enter. Just be prepared for a lot of fighting when you do. Getting through the Charleston Cave is no picnic. Quite the opposite, actually.

As you may have expected, Charleston Cave is full of Nightstalkers. You've never run into these creatures before (most likely), but rest assured, they're difficult little creatures to defeat. That's why we wanted you to have melee-ready followers like Rex and Lily here to help you. Nightstalkers are dog-like creatures that move quickly. They all use Stealth Boys (inadvertently), so you'll only hear them coming at you, and won't immediately see them until they take enough damage to be revealed. It's actually a good idea to explore this whole cave system (which isn't too big, and not at all maze-like), since killing Nightstalkers is a nice way to earn some experience points. Just be ready to heal yourself, especially if you're of a lower level, since Nightstalkers have the ability to do a hell of a lot of damage rather rapidly.

What you're looking for in the Charleston Cave as you explore and do battle is a room with a Nightkin body lying in it. It should be in the far side of the system, on the other side of some water that you have to wade through, in a room occupied by several Nightstalkers. If you examine this Nightkin's body, you'll uncover exactly what you were looking for -- a Chewed Stealth Boy. Right next to the Nightkin is his weapon, called Oh, Baby!. You may not want to use it, but it's extremely valuable, so it won't hurt you to grab it and bring it with you to sell later. Once you have those items in hand, and feel like you've seen enough of the cave, you can head back to the entrance, and then quick-travel back to Jacobstown. Once you arrive, speak with Dr. Henry and let him know that you've found an important clue.

It's at this point in the side quest, near the end, where things can take a bunch of different turns. How we proceeded isn't necessarily how you have to go about things, so keep that in mind moving forward. You need high Speech and Science skills to fully explore other avenues, but since we didn't, we kept it simple. After giving Dr. Herny the Chewed Stealth Boy, we opted to let him use Lily to run a new experiment (you'll need to speak with her to convince her to do so, however). Dr. Henry learns what he can from the experiment, and eventually, Lily is sent off, hopeful that her hard work and involvement in the new experiment might bring Dr. Henry closer to finding a cure.

But just as Lily runs off, a Nightkin named Keene runs in. Keene is decidedly more angry and hostile than Lily, and demands that Dr. Henry hands over the Chewed Stealth Boy. With very, very high Speech, you can convince him to go away, but otherwise, you're going to be forced to either fight and kill him and his friends, or simply let him take the Stealth Boy and run off. We opted to do the latter. This doesn't stop Dr. Henry from deriving important information from the experiment he's already run, and it ensures that nobody gets hurt. Once this end sequence has run its course, that's it. This side quest should conclude in victory (and a plethora of experience points, too).